Liquid level indicator



Feb. 17, 1959 v c. c, BAUERLEm 2,873,714

. LIQUID LEVEL INDICATOR Filed Aug. 15. 1956 I9 gs,

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Lzezziar C481 6: MJKIM/IV United States Patent Office 2,873,714 Patented Feb. 17, 1959 z,s1s,114 mourn LEVEL nsmcsron Carl C. Bauerlein, Lincolnwood, 111., assignor to The Dole Valve Company, Chicago, 111., a corporation of Illinois This invention relates to improvements in liquid level indicators and more particularly relates to such indicators adapted for concentrate dispensers and like devices for indicating when the container for the concentrate 1s em t r X principal object of the invention is to provide a simple and improved means to indicate a given level in a container, to enable a person to readily determine when the container is empty.

A further object of the invention is to provide a liquid level indicator particularly adapted for concentrate d18- pensers and the like'in which a beam of light is reflected from the concentrate in its container and is intercepted at a predetermined level of the concentrate with1n the container, to indicate when the container is substantially em ty.

These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawing showing a form of concentrate dispenser in side elevation with certain parts broken away and certain other parts shown in vertical section, in order to illustrate one form in which my invention may be embodied.

' In the drawing, I have shown for illustrative purposes a dispenser for proportioning and dispensing concentrates, and the like, from the container or can in which the concentrate is supplied.

The dispenser may include a cabinet or casing 10 having a base 11 which may be mounted on a counter or like support and having a glass rest 12, projecting outwardly from a front wall 13 thereof, and operating a water valve 15 for supplying water to proportion the concentrate contained in a can or container 16, contained in a refrigerated tank 17 of the dispenser.

The tank 17 is shown as having a cylindrical wall of suflicient diameter to accommodate the ready insertion and removal of the concentrate can 16 and as being of sulficient depth to contain the can, and accommodate the can to project over the top of the tank, so it may readily be grasped for removal therefrom. The casing 10, tank 17 and can 16 are shown as being closed by a detachable hood or cover 19. While I have herein shown a can serving as a concentrate containing chamber, it should be understood that the tank 17 may serve as a concentrate containing chamber if desired.

The tank 17 and can 16 may also be cooled by cooling coils 21, connected with a compressor and condenser of a refrigeratnig unit (not shown), and encircled by water circulating coils 22, supplying water under the control of the valve 15, to withdraw concentrate from the bottom of the can 16 and uniformly proportion the mixture of concentrate and water under the control of a proportioner 23, having communication with the bottom of the can 16 through a suction tube 24. The proportioner 23 has a venturi therein through which pressurized water is arranged to flow, causing suction at the suction tube and consequently the withdrawal of concentrate from the container 26. Before the concentrate and the water are dispensed from the proportioner 23 they are thoroughly mixed within the diverging wall portion of the venturi.

Referring now in particular to the indicator of my invention, for indicating the level of liquid or concentrate in the can 16 to enable it to be determined at a glam when the can 16 is empty, I have shown a source of light 25 mounted on the underside of the cover or hood 19, above the tank 17 and can 16, in position to project a beam of light into said can to reflect from liquid or concentrate 26 within said can for visual interception when the liquid or concentrate is at a given level, preferably adjacent the bottom of said can to indicate when the can is empty. The source of light 25 is shown as including a housing 27 depending from and mounted on the inside of the cover 19. The housing 27 may contain a socket 29 having a light bulb '30 therein, projecting a beam of light through a lens 31 arranged to direct a thin beam of light into the can 16 to the concentrate 26.

A reflector 33, herein shown as being in the form of a mirror is mounted within the cover 19 on the underside thereof in a casing 35, in such a position that when the concentrate reaches any predetermined given level such as when the can is nearly empty,the beam of light reflectd from the surface of the concentrate or liquid in the bottom of the can 16 will be intercepted by the reflector 33 and projected in a horizontal direction through a lens 36 in a front wall 37 of the hood or cover 19. The lens 36 may be a jeweled lens and may be colored red to call the attendants attention when the can 16 is empty.

The source of light 25 and angle of the beam projected thereby and the reflector 33 and the lens 36 are angularly disposed and spaced with respect to each other on the well known principle that the angle of reflection of a beam of light is equal to its angle of incidence. Therefore, a beam of light is continually projected through the lens 31 into the can 16, and the position of the reflected 'beam continually shifts in space as the level of liquid or concentrate in the can 16 drops. The beam of light, therefore, will only be intercepted by the reflector or mirror 33 and projected horizontally by the mirror through the lens 36 when the can 16 is empty, or nearly empty.

Itmay thus be seen that I have provided a simple inexpensive and practical indicator enabling a person to readily determine at a glance when a concentrate can is empty without opening the cover 19, and that this indicator has no moving parts and only requires the electrical connections necessary to illuminate the light bulb 25, which may either be illuminated by an external source of power or by a battery (not shown).

It will be understood that modifications and variations of the present invention may be effected without departing from the spirit and scope of the novel concepts thereof. 1

I claim as my invention:

In a liquid container, a casing for said container, a cover for said casing and container, means associated with said container for effecting the removal of liquid therefrom, and means on said cover for indicating a substantially empty condition of said container comprising a source of light mounted on said cover on the inside thereof adjacent one side of said container and having a lens projecting a thin beam of light into said container in an angular direction toward the center and bottom thereof, indicating means mounted on said cover adjacent the opposite side of the container from the source of light for intercepting a reflected 'beam of light projected by said References Cited in the file of this patent lens, the spacing between the source Of light and the indi- UNITED STATES PATENTS catlngmeans being determmed by the angles of incidence 1 706 857 M h 26 and reflection of the beam of light from liquid in the bot- 1'991'192 B 1929 tom of the container when the container is nearly empty, 5 2'606297 i Z 1935 whereby the indicating means will only intercept the bear n 2'62l808 1:11 g [358m whcn the 9011mm" is m a nearly pi condl 2,625,658 Robinson Jan. 195.3 

